An Electrochemical Understanding of Extraction of Silver Picrate by Benzo-3<i>m</i>-Crown-<i>m</i>Ethers (<i>m</i>= 5, 6) into 1,2-Dichloroethane and Dichloromethane  

作　　者：Yoshihiro Kudo Marina Ogihara Shoichi Katsuta Yasuyuki Takeda 

机构地区：[1]Graduate School of Science, Chiba University, Chiba, Japan

出　　处：《American Journal of Analytical Chemistry》2014年第7期433-444,共12页美国分析化学（英文）

摘　　要：Two extraction constants (Kex± and Kex) for extraction of silver picrate (Ag﹢Pic﹣) by benzo-15-crown-5 ether (B15C5) and benzo-18-crown-6 one (B18C6) into 1,2-dichloroethane (DCE) and dichloromethane (DCM) were determined at 298 K and given values of ionic strength. Here, Kex± and Kex were expressed as [AgL﹢]o[Pic﹣]o/[Ag﹢][L]o[Pic﹣] and [AgLPic]o/[Ag﹢][L]o[Pic﹣], respectively: L symbolizes B15C5 or B18C6 and the subscript “o” denotes the organic phase composed of DCE or DCM. Individual distribution constants (KD,Pic) of picrate ion, Pic﹣, into the two diluents were also determined with the determination of Kex. From comparison of these KD,Pic values with those standardized, interfacial potential differences () at extraction equilibria were evaluated. Then, using these values, relations of the experimentally-determined logKex± or logKex values with their electrochemically-standardized ones were precisely discussed. Consequently, it was indicated that logKex± should be expressed as a function of .Two extraction constants (Kex± and Kex) for extraction of silver picrate (Ag﹢Pic﹣) by benzo-15-crown-5 ether (B15C5) and benzo-18-crown-6 one (B18C6) into 1,2-dichloroethane (DCE) and dichloromethane (DCM) were determined at 298 K and given values of ionic strength. Here, Kex± and Kex were expressed as [AgL﹢]o[Pic﹣]o/[Ag﹢][L]o[Pic﹣] and [AgLPic]o/[Ag﹢][L]o[Pic﹣], respectively: L symbolizes B15C5 or B18C6 and the subscript “o” denotes the organic phase composed of DCE or DCM. Individual distribution constants (KD,Pic) of picrate ion, Pic﹣, into the two diluents were also determined with the determination of Kex. From comparison of these KD,Pic values with those standardized, interfacial potential differences () at extraction equilibria were evaluated. Then, using these values, relations of the experimentally-determined logKex± or logKex values with their electrochemically-standardized ones were precisely discussed. Consequently, it was indicated that logKex± should be expressed as a function of .

关 键 词：Individual Distribution CONSTANTS Interfacial Potential Differences Standardized Extraction CONSTANTS Silver PICRATE Benzo Crown ETHERS Dihaloalkanes 

分 类 号：O6[理学—化学]